In doing extensive research to try and rid an expensive Bernina sewing machine of an absolutely horrid cigarette smell (that we found at an estate sale), it was advised that we seal it up placing a cup of ammonia or white vinegar inside the case overnight. We did this. First, we tried the ammonia and it helped somewhat. Then a few days later we tried the white vinegar.
People. Take this as a bit of caution, warning, or for whatever it is worth. DO NOT EVER use vinegar. What was a nice shiny barely used machine, now is PITTED from all the rust and corrosion.
Lesson certainly learned - but a very costly one at that.